From c203e90af6e02b3b59295b63981ce6d69b35fbdf Mon Sep 17 00:00:00 2001
From: bdring <barton.dring@gmail.com>
Date: Fri, 29 Sep 2023 13:25:24 -0500
Subject: [PATCH] Optimize coolant delays

Removed M9 delay
Delay does not occur if M7 or M8 state does not change
---
 FluidNC/src/CoolantControl.cpp | 10 +++++++---
 FluidNC/src/CoolantControl.h   |  2 ++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/FluidNC/src/CoolantControl.cpp b/FluidNC/src/CoolantControl.cpp
index 7daa6d1a1..38583f108 100644
--- a/FluidNC/src/CoolantControl.cpp
+++ b/FluidNC/src/CoolantControl.cpp
@@ -53,6 +53,8 @@ void CoolantControl::write(CoolantState state) {
         bool pinState = state.Mist;
         _mist.synchronousWrite(pinState);
     }
+
+    _previous_state = state;
 }
 
 // Directly called by coolant_init(), coolant_set_state(), which can be at
@@ -68,11 +70,13 @@ void CoolantControl::stop() {
 // parser program end, and g-code parser CoolantControl::sync().
 
 void CoolantControl::set_state(CoolantState state) {
-    if (sys.abort) {
-        return;  // Block during abort.
+    if (sys.abort || (_previous_state.Mist == state.Mist && _previous_state.Flood == state.Flood)) {
+        return;  // Block during abort or if no change
     }
     write(state);
-    delay_msec(_delay_ms, DwellMode::SysSuspend);
+
+    if (state.Mist || state.Flood)  // ignore delay on turn off
+        delay_msec(_delay_ms, DwellMode::SysSuspend);
 }
 
 void CoolantControl::off() {
diff --git a/FluidNC/src/CoolantControl.h b/FluidNC/src/CoolantControl.h
index 4726e4fb0..c4c368947 100644
--- a/FluidNC/src/CoolantControl.h
+++ b/FluidNC/src/CoolantControl.h
@@ -13,6 +13,8 @@ class CoolantControl : public Configuration::Configurable {
 
     uint32_t _delay_ms = 0;
 
+    CoolantState _previous_state = {};
+
     void write(CoolantState state);
 
 public: